I say that the answere would be B
85)
The bone structure from outside would be periosteum, cortical, cancellous then medulla. Periosteum is the area outside the bone that will supply nutrition into the outer part of the bone. Cortical is the layer where bone mineral deposition is intense. In this part, the bone is compact and hard. This is the part of the bone that has great strength.
Cancellous is part of the bone where it is not too hard but not too soft. Mineralization is not so dense like cortical layer. That makes this part looks spongy.
In the medulla, most part is made from connective tissue and blood vessels. This part is responsible for the bone vascularization, which means the supply of mineral to the outer part is coming from the medulla. Mineralization is not much in the medulla, makes it not strong. Medulla or marrow also makes blood cells.
86)
The region of the spine would be cervical(neck), thoracal(chest), lumbar(back), sacrum then coccyx. The vertebrae in the neck are smaller since it did not need much strength but need more mobility. Lower part on the thoracal and lumbar is bigger and have a bigger process that will further stabilize the vertebrae. Thoracal vertebrae have a part on their side where the ribs attached. Sacrum shape was a kinda weird because it needs to be able to connect with the pelvis to make buttock. Coccyx the tailbone look like just a small remnant and doesn't seem to have a function in human.
87)
Axis is the name of cervical 2nd vertebral which was located below the atlas, 1st cervical vertebrae. Both of them doesn't have spinal processes that were stabilizing the side of vertebrae Axis also has an odontoid peg which will make the joint with atlas more flexible.
This effect makes the neck can turn to side easily. It also makes neck more mobile vertically, make a nodding movement is possible.
88)
Thre kind of joints would be: Synarthrosis, amphiarthrosis, and diarthrosis.
In synarthrosis, the joint mostly made by fibrous so that it can move. The example of this joint would be suture in the skull. In children, the skull joint is not closed to permit the head to grow but in the adult, it is closed.
Amphiarthrosis joint permits a small movement. This included the intervertebral disc.
Diarthrosis permit a wide degree of movement. This joint is more complex because it has the synovial membrane. The complex structure makes the joints more durable to shock. This was vital because organ with this join used frequently. The example of this joints would be femur and pelvic(hip) joints. Joints in arm and leg mostly diarthrosis joint.
When a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star.This explosion made waves in space which squeezed the cloud of gas & dust.
Answer:
2
Explanation:
İf system ideal ( no frictional force )
Fnet=m.a
20=10.a
a=2m/s2
